Method of manufacturing steel.



ToialZ whom it may concern:

drawing.

sired percentage of carbon.

it known that 1, JOHN W. MAX ELL, a citizenof' the United StatesofAmerica;'-re

siding at VVilliamsport, in the county of Lyeoming and "State ofPennsylvania, have invented certain new and useful Improve-1 ments inMethods ofManufacturing Steel,- v of which the following is aspecification, referencebeing had therein to the accompanying Thisinvention has relation to a method of manul'acturir'ig steel and has foritsobject the provision of a novel method of manufacturing steel by abasic open-hearth process; In the ordinary open-hearthv process a batchof metal composed- 0f pig iron and scrap .iron and-steel usually in thepropor "tion of about 75% of pig iron to 25% of scrap iron or steel areplaced in an open-hearth furnace together with limestone and melted,

the usual met'hodbeing to charge the fur nace first with limestone, thenwith, the pig iron and finallywith the scrap iron or steel. After thematerials are melted the charge is refined by adding more limestone andsome form of 1IOI1 OXl(l, usually IIOIl ore, fiuor spar and other agentsand when-the desired state of purity has been reached if low carbonsteelis desired, the batch is tapped out, but ifhigh carbon steel isdesired it is secured by the-addition of ferro manganese orspiegeleiaenor else pure pig iron to obtain the de lnflmy improvedmethod the pig-iron in small quantities and preferably a neutralpig-iron, that is apig-iron low in silicon and phosphorus, together withlimestone, lime or other suitable material containing calcium are firstcharged in an open-hearth furnace of the ordinary orany suitable type. A

' quantity'of carbonaceous material prefer= ably in the form ofcharcoal, coal or coke, is then quickly spread over the charge ofIpig-iron and limestone, the quantity of such carbonaceous materialemployed bemgsuflivc-lent to give the requlred or a greater percentageof carbon than is necessary to secure the-required percentage of carbonin the -finished stock. This carbonaceous material is thenquicklycovered by the scrap iron or steel to be used, so as to protectit from ex-l posure to the free oxygen in the flame in the furnace, asmy ob ect 1n using a carbonaceousmaterial 13.1 this'way is not. tosecure earne on Joan W. inmat orwtttir iseoirr PENN when I Specificationof Letters Patent.

METHOD or rrawotene'rnnnts STEEL; i

. Patented Oct; 6,1908.

"Application filed February 20,1908. sensin 302,124. 7

charge melts, add. more of thc'carbonaceous' material and cover it withmore of the scrap iron, or steel and carry the process along in thismanner until all the required carbonaceous material and scrap iron orsteel have been charged and melted dorm. Muchhow ever, dependsv on thecondition of the hearth.

and the working of the furnace and it is sometimes found desirable tocharge a part of the scrap iron or steel first, then the limestone, thenmore of the scrap iron or steel,

then the charcoal or coke, and then cover the a charcoal or coke withthe remainder of the vscrap iron or steel, the essential point to bekept in vi'eu being to so arrange the mate rials as to brmg thecarbonaceous manna;

into close contact with the scrap iron or' steel and at the same time toprotectit from combustion by the free oxygen in the flame in thefurnace, r

" When thus treated, a charge of scrap iron or steel absorbs or takes upenough carbon,

during-the melting period to not only lower their melting point enoughso that they are readily melted at the ordinary temperature maintainedin an open hearth furnace but also to produc-esteel of very high carbonfrom very pure materials if so desired. After the charge has been melteddown as above described, the -refining of the bath is thenproceeded-with in the ordinary manner, and after the required refininghas been accomplished and the carbon reduced to the desired percentagethe bath is tapped out of the furnace,;the' usual final addition offerro- Imanganese, ferro-silicon, aluminum, etc, and

such other materialand materials as are usually employed to producealloys where alloys are desired, being added either in the furnace or inthe ladle.

-. Heretofore ithas been considered impracticable to melt a charge ofpure wrought iron in an open, hearth furnace without the addiof. steelof any carbon desired from very soft to extremely hard are readilyproduced from charges of iron and steel scrap with the use of pi iron.Steel of very fine quality may thus e produced with great uniformityfrom verycheap materials.

I claim: a

1. The method of manufacturing steel consisting in charging an openhearth furnace with a calcareous material such as limestone or lime, acarbonaceous material or materials, and scrap' iron or steel, the wholebeing charged in such a manner as to bring the scrap iron or steel intointimhte contact with the carbonaceous -material or materials and 5 atthe same time to protect the carbonaceous material or materials fromoxidation by the free oxygen in the furnace, then melting the charge andcompleting the refining thereof in the usual manner, and finallyremoving it from the furnace.

2, The: method of manufacturing steel, consisting in charging an openhearth fur-'- nace with pig iron and a calcareous material such aslimestone or lime, then a carbonaceous materlal or materials, andfinally covering the same with wrought iron or steel and then meltingand refining the charge in the usual manir'r and tapping from thefurnace.

3. The method of manufacturing steel,

consisting in placing a charge 0f pig iron and material containingcalcium in an open hearth furnace, then lacing on this chargecarbonaceous materiafcovered by scrap iron or steel, and then meltingthe c large:

In testimony whereof I affix my signature in the presence of twowitnesses.

JOHN W. MAXWELL. \Vitnesses:

J. B. CONNOLLY, CHARLES LowELL HOWARD.

